Fish bioenergetics, introduction

Compiled by Dan Galeriu for EMRAS II WG7

Aix en Provence 6-9 September 2010

What is Bioenergetics?

“…..the study of the flow and transformation of energy in and between living organisms and

between living organisms and their environment”

Consumption = Income

Bioenergetics ~ Economics

Growth = Savings and Investments

Metabolism = Rent Wastes & Losses = Taxes

Consumption = Metabolism + Waste + Growth

Model Components:

Consumption

C =

Gonads �Reproduction

∆Biomass� Growth

+ (∆B + G)

Respiration� Basal Metabolism

Active Metabolism� Costs from activity

Specific Dynamic Action� Costs from digestion

(R + A + S)

Egestion-F & Excretion -U

+ (F + U)

Typical Energy Budgets Differ for Carnivores & Herbivores:

2043 +37 +100 =Herbivores2927 +44 +100 =Carnivore

GrowthWasteRespirationConsumptionNormalized Percentages

Largescale Stoneroller

Green Sunfish

Muskellunge

All processes are temp. and size dependentSp

ecific

Rate

(g/g/

d) 0.08

0.06

0.04

0.02

0.00

5 10 15 20 25 30

Temperature (C)

growth

SDA

excretionegestion

Ma x . C o n s u m p ti o n = C m a x

starvation

Upper lethal

loss of growth

respiration

“Golden Banana”

Too hot,body starts to fail

What else do we need to run the model?

Temperatures where fish live…• alewife - 20° C• bluegill - 29° C• coho salmon - 15° C• largemouth bass – 27.5° C • muskellunge - 26° C• northern pike - 24° C • rainbow smelt - 13° C

• rainbow trout - 20° C• striped bass – 21.6° C• walleye - 22° C• yellow perch - 26° C• smallmouth bass – 29 ° C• sea lamprey - 18° C• chinook salmon - 15° C

What do we need to run the model?

What a fish eats …

What do we need to run the model?

Prey and Predator Energy Densities …

Zooplankton – 2513 j/g wet mass

Leech – 24000 j/g dry mass

Snails – 18000 j/g dry mass

Crayfish – 3766 j/g wet mass

Alewife – 7225 j/g wet mass

Yellow Perch – 5000 j/g dry mass

What do we need to run the model?Basic physiological parameters…• Egestion (size/temp dependent) � F• Excretion (size/temp dependent) � U• Specific Dynamic Action � SDA• Basal Metabolism � R• Active Metabolism � A

Where do we get all these….? - We do painstakingly difficult lab experiments (imagine having to measure fish excrement or…)- We steal them, I mean “borrow” them!- Species borrowing is common, it can cause problems- Should evaluate and test if borrowing is appropriate